In the North west area of Skyrim, slightly north west of Rorikstead, there is the Shrine of Peryite (coming here will start a Daedric quest and there is a speech skill book on the table). Behind the shrine to the east, at the bottom of the mountain are the 'roots' of the shrine. Here you can find a dead Wood Elf (once you kill the wolf that may be located there), as well as a chest containing random loot and an illusion skill book, and next to the pillar there is a couple potions, some ingredients, and a diamond. Even if you don't need elf blood, it's well worth the trip just for the Daedric quest. If you do go for the quest, bring with you a silver ingot, a deathbell, a Flawless Ruby, and some vampire dust. It will save you a trip.